class TestA { public void start() { System.out.println(”TestA”); } } public class TestB extends TestA { public void start() { System.out.println(”TestB”); } public static void main(String[] args) { ((TestA)new TestB()).start(); } } What is the result?() A、 TestAB、 TestBC、 Compilation fails.D、 An exception is thrown at runtime.
class TestA { public void start() { System.out.println(”TestA”); } } public class TestB extends TestA { public void start() { System.out.println(”TestB”); } public static void main(String[] args) { ((TestA)new TestB()).start(); } } What is the result?()
- A、 TestA
- B、 TestB
- C、 Compilation fails.
- D、 An exception is thrown at runtime.
相关考题:
通过实现Rmmable接口创建线程,请在下面横线处填写代码完成此程序。public class ThreadTest{public static void main(String args []){Thread testObj1 = new Thread (new Hello ());Thread testObj2 = new Thread (new Hello ());testObj 2.start ( );}}class Hello implements Runnable{int j;public void run(){System.out.println("Hello" + j ++);}}
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请在下划线处填入代码,是程序正常运行并且输出 “ Hello! ”Class Test 【 15 】 {Public static void main (String[] arge){Test t = new Test();t.start();}Public void run(){System.out.println( “ Hello! ” );}
现有:classTestA{publicvoidstart(){System.out.println(TestA);}}publicclassTestBextendsTestA{publicvoidstart(){System.out.println(TestB);}publicstaticvoidmain (string[]args)(((TestA)newTestB()).start();)}运行结果是哪项?()A.TeStAB.TeStBC.编译失败D.运行时抛出异常
classTestA{publicvoidstart(){System.out.println(”TestA”);}}publicclassTestBextendsTestA{publicvoidstart(){System.out.println(”TestB”);}publicstaticvoidmain(String[]args){((TestA)newTestB()).start();}}Whatistheresult?()A.TestAB.TestBC.Compilationfails.D.Anexceptionisthrownatruntime.
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interface A{int x = 0;}class B{int x =1;}class C extends B implements A {public void pX(){System.out.println(x);}public static void main(String[] args) {new C().pX();}}
使下列程序正常运行并且输出“Hello!”,横线处应填写的内容是( )。 class Test { public static void main(string[]args){ Test t=new Test; start; } Public void run{ System.out.println("Hello!¨); )A.extends ThreadB.extends FloatC.extends IostreamD.extends Stdio
阅读下面程序 public class Test2 ______ { public static void main(String[] args) { Thread t=new Test2(); t.start(); } public void run() { System.out.println("How are you."); } } 程序中下画线处应填入的正确选项是A.implements ThreadB.extends RunnableC.implements RunnableD.extends Thread
( 30 )在程序的下划线处应填入的选项是public class Test _________{public static void main(String args[]){Test t = new Test();Thread tt = new Thread(t);tt.start();}public void run(){for(int i=0;i5;i++){system.out.println( " i= " +i);}}}A ) implements RunnableB ) extends ThreadC ) implements ThreadD ) extends Runnable
class MyThread extends Thread { public void run() { System.out.println(“AAA”); } public void run(Runnable r) { System.out.println(“BBB”); } public static void main(String[] args) { new Thread(new MyThread()).start(); } } What is the result?() A、 AAAB、 BBBC、 Compilation fails.D、 The code runs with no output.
1. class TestA { 2. TestB b; 3. TestA() { 4. b = new TestB(this); 5. } 6. } 7. class TestB { 8. TestA a; 9. TestB(TestA a) { 10. this.a = a; 11. } 12. } 13. class TestAll { 14. public static void main (String args[]) { 15. new TestAll().makeThings(); 16. // ...code continues on 17. } 18. void makeThings() { 19. TestA test = new TestA(); 20. } 21. } Which two statements are true after line 15, before main completes?()A、 Line 15 causes a stack overflow.B、 An exception is thrown at runtime.C、 The object referenced by a is eligible for garbage collection.D、 The object referenced by b is eligible for garbage collection.E、 The object referenced by a is not eligible for garbage collection.F、 The object referenced by b is not eligible for garbage collection.
class A { public A() { System.out.println(“hello from a”); } } class B extends A { public B () { System.out.println(“hello from b”); super(); } } public class Test { public static void main(String args[]) { A a = new B(); } } What is the result when main is executed?() A、 Compilation fails.B、 hello from aC、 hello from bD、 hello from b hello from aE、 hello from a hello from b
class Super { public int i = 0; public Super(String text) { i = 1; } } public class Sub extends Super { public Sub(String text) { i = 2; } public static void main(String args[]) { Sub sub = new Sub(“Hello”); System.out.println(sub.i); } } What is the result?() A、 0B、 1C、 2D、 Compilation fails.
public class A extends Thread { A() { setDaemon(true); } public void run() { (new B()).start(); try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“A done”); } class B extends Thread { public void run() { try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“B done”); } } public static void main(String[] args) { (new A()).start(); } } What is the result?() A、 A doneB、 B doneC、 A done B doneD、 B done A doneE、 There is no exception that the application will print anything.F、 The application outputs “A done” and “B done”, in no guaranteed order.
Public class test ( Public static void stringReplace (String text) ( Text = text.replace (‘j’ , ‘i’); ) public static void bufferReplace (StringBuffer text) ( text = text.append (“C”) ) public static void main (String args[]} ( String textString = new String (“java”); StringBuffer text BufferString = new StringBuffer (“java”); stringReplace (textString); bufferReplace (textBuffer); System.out.printLn (textString + textBuffer); ) ) What is the output?()
现有: class TestA { public void start() { System.out.println("TestA"); } } public class TestB extends TestA { public void start() { System.out.println("TestB"); } public static void main (string[] args) ( ((TestA)new TestB()).start(); ) } 运行结果是哪项?() A、 TeStAB、 TeStBC、编译失败D、运行时抛出异常
public class TestA{ public void methodA() throws IOException{ //…… } } public class TestB extends TestA{ public void methodA() throws EOFException{ //…… } } public class TestC extends TestA{ public void methodA() throws Exception{ //…… } } 当编译类TestC的时候,结果是哪项?() A、 正常B、 编译错误C、 运行错误D、 以上都不对
public class Starter extends Thread { private int x= 2; public static void main(String[] args) throws Exception { new Starter().makeItSo(); } public Starter() { x=5; start(); } public void makeItSo() throws Exception { join(); x=x- 1; System.out.println(x); } public void run() { x *= 2; } } What is the output if the main() method is rum?() A、 4B、 5C、 8D、 9E、 Compilation fails.F、 An exception is thrown at runtime.G、 It is impossible to determine for certain.
1. interface TestA { String toString(); } 2. public class Test { 3. public static void main(String[] args) { 4. System.out.println(new TestA() { 5. public String toString() { return “test”; } 6. } 7. } 8. } What is the result?() A、 testB、 nullC、 An exception is thrown at runtime.D、 Compilation fails because of an error in line 1.E、 Compilation fails because of an error in line 4.F、 Compilation fails because of an error in line 5.
单选题class MyThread extends Thread { public void run() { System.out.println(“AAA”); } public void run(Runnable r) { System.out.println(“BBB”); } public static void main(String[] args) { new Thread(new MyThread()).start(); } } What is the result?()A AAAB BBBC Compilation fails.D The code runs with no output.
单选题public class Starter extends Thread { private int x= 2; public static void main(String[] args) throws Exception { new Starter().makeItSo(); } public Starter() { x=5; start(); } public void makeItSo() throws Exception { join(); x=x- 1; System.out.println(x); } public void run() { x *= 2; } } What is the output if the main() method is rum?()A 4B 5C 8D 9E Compilation fails.F An exception is thrown at runtime.G It is impossible to determine for certain.
单选题public class TestA{ public void methodA() throws IOException{ //…… } } public class TestB extends TestA{ public void methodA() throws EOFException{ //…… } } public class TestC extends TestA{ public void methodA() throws Exception{ //…… } } 当编译类TestC的时候,结果是哪项?()A 正常B 编译错误C 运行错误D 以上都不对
单选题class TestA { public void start() { System.out.println(”TestA”); } } public class TestB extends TestA { public void start() { System.out.println(”TestB”); } public static void main(String[] args) { ((TestA)new TestB()).start(); } } What is the result?()A TestAB TestBC Compilation fails.D An exception is thrown at runtime.
单选题现有: class TestA { public void start() { System.out.println("TestA"); } } public class TestB extends TestA { public void start() { System.out.println("TestB"); } public static void main (string[] args) ( ((TestA)new TestB()).start(); ) } 运行结果是哪项?()A TeStAB TeStBC编译失败D运行时抛出异常
多选题1. class TestA { 2. TestB b; 3. TestA() { 4. b = new TestB(this); 5. } 6. } 7. class TestB { 8. TestA a; 9. TestB(TestA a) { 10. this.a = a; 11. } 12. } 13. class TestAll { 14. public static void main (String args[]) { 15. new TestAll().makeThings(); 16. // ...code continues on 17. } 18. void makeThings() { 19. TestA test = new TestA(); 20. } 21. } Which two statements are true after line 15, before main completes?()ALine 15 causes a stack overflow.BAn exception is thrown at runtime.CThe object referenced by a is eligible for garbage collection.DThe object referenced by b is eligible for garbage collection.EThe object referenced by a is not eligible for garbage collection.FThe object referenced by b is not eligible for garbage collection.
单选题public class A extends Thread { A() { setDaemon(true); } public void run() { (new B()).start(); try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“A done”); } class B extends Thread { public void run() { try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“B done”); } } public static void main(String[] args) { (new A()).start(); } } What is the result?()A A doneB B doneC A done B doneD B done A doneE There is no exception that the application will print anything.F The application outputs “A done” and “B done”, in no guaranteed order.